Light fixture



June 7, 1966 E. w. cHADwlcK 3,255,345

LIGHT FIXTURE Filed Sept. 5, 1963 2 SheeS-Shee; l

INVLNTOR ERIC W. CHADWICK.

June 7, 1966 E. w. cHADwlcK 3,255,345

LIGHT FIXTURE Filed Sept. 5, 1963 2 Sheets-Sheet 2 lNvENTOR ERIC W. CHADWICK.

United States Patent O 3,255,345 LIGHT FIXTURE Eric W. Chadwick, 2318 NE. 125th, Seattle, Wash. Filed sept. s, 196s, ser. No. 306,212 12 Claims. (Cl. 240-47) This invention relates to a light fixture which is particularly adaptable and useful to provide proper operation of incandescent lamps, specifically the iodine quartz lamps which provide an extremely high lumen maintenance through the operation of the iodine regeneration cycle, and other light lamps in which high operating temperatures are required.

Most electric lamps, and especially those of the tungsten lilament type generate radiant energy having wave lengths encompassing the physical spectrum together with the shorter wave length of ultra violet energy and the longer wave lengths of infra red energy, the latter being the heat energy of radiation.

In the use of artificial illumination, to display wares such as clothing and the like, it is important that as much f of the shorter wave length radiation of the light source be directed on the article to be displayed and that as much as possible of the longer wave length radiation be eliminated from the light column which is usually beamed towards articles with suitable reflectors. The recent development of the iodine quartz electric lamp has provided an excellent source of intense light which may be most advantageously used for commercial display purposes due firstly to the relatively high radiant energy output of the filament and due to the high lumen maintenance thereof. The proper operation of the iodine quartz lamp requires operation temperatures in excess of 250 C. (generally 500 C.) in order for efficient operation of the iodine regeneration cycle. It has been found however that this lamp which in the standard form has a tungsten filament centrally located in a cylindrical quartz envelope, the ends of the envelope being sealed and provided with ceramic tips,has a relatively short life span due to the disintegration of the ceramic tips when the lamp is operated at the relatively high temperatures aforesaid. The high temperatures also materially effect the leads to the lamp and their connections thereto.

It is appreciated that a number of attempts have been made to providelight xtures and reflectors intended to permit the lamp to operate at higher temperatures yet to prevent the heat ordinarily generated by the lamp from affecting the ceramic -tips and'leads thereof. However, these attempts have not been, in the main, successful and the relatively short life of the iodine tungsten lamp still remains a problem.

The present invention overcomes the above problems by providing a light fixture and reflector in which the longer radiant waves of heat energy are in great measure removed from the visible light beam, being filtered through the reflector and, instead of being dissipated, areused to cause cooling convection currents of air to flow over the end seals and leads of the lamp to thereby cool the latter. The reflector is so arranged -to preventcooling drafts of air from cooling the quartz envelope and effecting the iodine regeneration cycle.

The present invention consistsof a light fixture or lamp that operates at high temperatures and has at least one seal at one end thereof, a reflector, a filter in and forming partof the reflector, said filter being adapted to transmit infra-red rays therethrough and to reflect therefrom substantially all other rays having a wave length shorter than said infra-red rays, holding means for supporting a high temperature lamp in front of the reflector and the filter, a heating chamber formed behind the reflector and into which infra-red rays are directed by the filter to heat the air in said chamber, and passage means at said holding means and through which air can travel over each lamp seal held by said holding means, said passage means being located relative to the heating chamber so that heat in the latter causes air to travel through the passage meansl to cool each end seal during the operation of the lamp and fixture..

In the drawings which illustrate the embodiments of the invention,

FIGURE l is an isometric view partially in section of one embodiment of the invention,

FIGURE 2 is a front elevation of a portion of the embodiment as illustrated in FIGURE l showing the lamp, filter, and holders for the lamp,

FIGURE 3 is a section on line 3--3 of FIGURE 2,

FIGURE 4 is an isometric view partially cut away of another embodiment of the invention, and

FIGURE 5 is a front elevation of a portion of the embodiment as illustrated in FIGURE 4 showing the lamp,

filter and holders for the lamp.

Referring to the drawings and with particular reference to FIGURES l, 2 and 3, the light fixture 10 which is so arranged so as to project the light therefrom substantially downwardly comprises a vertical tubular casing 11 closed at its upper end 12 by a cover plate 14 and closed at its lower end 15 by a suitable lens or glass plate 16 which is supported in position on an inner annular lip 18 of an annular bracket 19, said bracket fitting over said lower end 15 of the tubular casing and being secured thereto by screws or by any other suitable means. A reflector 22V which in the present form of the invention is a highly polished metallic plate is mounted within the casing 11 near the lower end thereof and normal to the longitudinal axis of the casing and substantially filling the casing so as to prevent the passage of air thereby.

The reflector 22 is provided with a centrally located substantially rectangular aperture 23 and, mounted on the reflector and substantially filling the aperture is a dichroic filter 25 which has the properties of being able to transmit infra red waves therethrough and to reflect visible light waves and ultra violet light waves therefrom. It may be mentioned herethat filters having the foregoing properties are in common usage today and are generally comprised of a transparent carrier such as glass having a metallic coating on one side thereof. The metallic coating provides a reflective surface and dependent upon the thickness thereof will permit the transmission of light waves of predetermined length therethrough. It is desired for the purposes of this invention that the thickness of the metallic coating should be such as to transmit only the longer infra red waves of radiant energy and to reflect the shorter waves of visible and ultra violet radiant energy.

The filter is a little larger than the aperture 23 and is supported by the upper side of the reflector being secured thereon by spring clips 26 which are themselves secured to the reflector by suitable fasteners such as bolts or rivets.I

The lter 25 forms the lower end of a heating chamber 29, the walls of -which comprise a pair of substantially rectangular plates 30 and 31 spaced on either side of the aperture' 23 at their lower ends 33 and 34 and extending towards the upper end 12 of the casing 11. The width of the plates are such that they snugly fit within the casing 1!1 so that those portions of the casings 35 and 86 lying between the edges of the plates -30 and 31 also serve as side walls for the heating chamber. The heating chamber is closed at its upper end by V-shaped deilectorbafiles 39 and 40. The plates 30 and 31 are fastened to the reflector by suitable angleconnectors 42 and have side portions 44 extending downwardly past the rellector to the lower end of the casing through a suitably fitting aperture formed in the reflector and lying at either end of the lter 25, thereby forming passageways 46 and 47 extending yfrom beneathy the reliector 22 and communicating with the heating chamber 29 thereof. The lower ends of the said passageways 46 and 47 are closed by reiiectorized facing plates 48 and 49 respectively extending along the lower edges of the side portions 44 of the plates 3G and 31 from the casing A11 to the lower surface of the reector 22. Apertures 52 formed in the casing 11 near the lower end of the passageways 46 and 47 permit the entry of air into said lpassageways and thence into the heating chamber 29 to be heated therein and then exhausted through suit-able apertures 55 formed near the upper end 12 of said casing.

The lamp 58 is preferably, as hereinbefore mentioned, of the iodine quartz type although it will be appreciated that other lamps of a similar nature might -be used. The iodine quartz lamp comprises an elongated tubular quartz envelope 60 in which a long tungsten filament is co-axially mounted, each end of the filament being connected to connectors 62 which pass through ceramic tips 63 at each end of the glass envelope.

A pair of sockets 65 provided with leads 65a connected to a suitable source of electrical power composed of a ceramic material are mounted in passageways 46 and 47 respectively, in soc-ket holders 66, each of said socket holders having a base plate 67 connected `to the upper end of the corresponding facing plates 48 and 49 by nuts and bolts 68 and spaced outwardly therefrom by sleeves 69 which are carried over the bolts between the facing plate and base plates. Apertures 71 formed in the upper end of the facing plate provide entry therethrough for the ceramic tips of the lamp to thereby permit installation of the said ceramic tips within the socket 65.

The li-ght xture 10 is arranged to be supported in a vertical position with the reflector and lamp disposed to project a beam of light downwardly. In this vertical position, the infra red or heat rays emanating from the la-mp are transmitted through the iilter 25 to heat the air withinthe heating cha-mber 29. The heated air rises and passes outwardly of the casing through apertures S. Cooling air therefor enters into the heating chamber via apertures 53 and passageways 46 and 47, thereby cooling the sockets 65 and the ceramic sealing tips 63 of the lamp. It will be seen however that the lamp lies within the contines of the reflector and that portion of the casing which lies downwardly from the reector. The air within the space so defined is heated by the lamp but cannot pass upwardly past the retiector. Consequently, the air within the space so defined remains at a relatively high temperature and no cooling drafts are permitted to pass over the envelope to thereby impair the eiiiciency of the iodine regeneration cycle. It should be further noted that the removal of a great part of the infra red rays from the Avlight column projected downwardly provides a light which, by reason of its relative lightness is admirably suited to illuminate articles on display.

FIGURIES 4 land 5 illustrate another form of the invention. In this form, the -light fixture 80 comprises a substantially vertical casing 81 having a perforated cover plate 83 closing the upper end thereof and a rerector 84 near the lower end thereof. The reliector 84 instead of completely filling the casing like reiiector 22 hereinbefore mentioned, is provided with a pair of downwardly-turned side panels 86 and 87 which are spaced inwardly `from the walls of the casing 81 to form passageways 89 and 90 respectively therebetween. A pair of chimney like brackets 92 and 93 extend longitudinally of the casing from the perforated cover plate 83 at its upper end downwardly through the two passageways S9 and 90 and outwardly beyond the lower edge 95 of the casing 81. Sockets 97 Iand 98 are mounted within the chimney like brackets 92 and 93 in some-what the same manner as sockets 65 are mounted within passageways `46 and 47 of the preceding fixture and are aligned with apertures 101 and 102 in the side panels 36 and 87 and apertures 103 and 104 formed in the lower end of the chimneys 92 and 93 to ypermit a lamp as hereinbefore described to be mounted within the sockets. The walls of the chimneys 92 and 93 extending above the reflector 84 are anodized to present a su-rface adapted to absorb heat. A dichroic filter |106 having the same properties as filter -25 is mounted in somewhat the same manner as said filter 25 above an aper-ture 197 formed in reiiector 814.

Light fixture yS0 operates in somewhat a different manner than light lfixture 19. In light fixture Si), the air above reliector l84, is heated by vthe infra red rays passing through the filter 196 and passes outwardly through the perforated cover 83, cooler air passing upwardly through passageways 89 and 9i). The heated air moving upwardly through the casing also heats the upper part of the anodized chimneys 92. and 93, said chimneys transmitting heat to the air lying therewithin. Light fixture is provided with lens or glass plate at the lo-wer end thereof and supported in an annular collar 108, said annular collar being spaced radially outwardly from the casing to permit the passage of air therebetween and being secured thereto by suitable angle connectors l109. The heated air within chimneys 92 and 93 also passes outwardly through the perforated cover drawing the cooling air through the space between the annular collar 109 and casing 81 and upwardly through `the lower ends of said chimneys, said cooling air passing over the lamp sockets contained therein. This latter form of the invention is suitable for outdoor lighting in areas subject to extremely 1low temperatures where only a minimum amount of cooling air is necessary to Imaintain proper cooling of the lamp sockets.

What I claim as my invention is:

1. In a light fixture Ifor a lamp that operates at high temperatures and has at least one seal at an end thereof, a reflector, a filter in the forming part of Itihe reiiector, said lter bein-g ladapted Ito transmit infradred .rays therethrough and to reflect therefrom substantially all other rays having a wave length shorter than said infra-.red rays, holding means for supporting a high temperature lamp in front of .the reflector and the filter, ,a heating chamber formed behind the reflector and into which .infra-red rays are directed by the tilter to heat Ithe .air -in said chamber, and passage means at said holding means and through which air can travel over each lamp seal held by said holding means, said passage means being located relative tothe heatin-g chamber so that heat in the latter causes air to travel through the passage means to cool each lamp seal .duning the operation of the lamp and fixture, said filter comprising a transparent carrier having a reective film coating on at least one surface thereof.

2. In a light hx-ture for a lamp that operates at high temperatures an-d has at lleast one seal at an end thereof, a reflector, a fil-ter in and forming part of the reector, said filter being adapted to transmit infra-red rays therethrough and tto reiiect therefrom substantially all other rays having a wave length shorter than said infra-red rays, holding `means rfor supporting a high temperature lamp in front of the reflector and the flilter, .a heating chamber formed behind the reflector and into which infra-red rays are directed by the lter to heat the air 'in said chamber, passage means at said holding means and through which air can travel over each lamp seal held by said holding means, said passage means being located relative to the heating chamber so that heat in the latter causes a-ir to rt-ravel through the passage means to cool each lamp seal during the operation of the lamp and fixture, and shielding means surrounding the lamp to prevent the passage of air currents therefove-r.

3. A light fixture for a lamp as claimed in claim 2 in which the shielding means comprises a continuous skirt connected to and surrounding the reflector and defining the periphery thereof, said skirt projecting outwardly in front of the reflector to confine :the lamp therewithin.

4. A light -ixture for a lamp as claimed in claim 2 in which the lamp has an iodine regeneration cycle.

`5. A light fixture for a lamp as claimed in claim 2 in which the passage means communicates with the heating chamber.

6. A light ixture ffor a lamp as claimed in claim 2 in which the passage means extends through the heating chamber and has a heat transmitting surface whereby heat within ythe heating chamber is Itransferred Ithrough said surface to heat the ,air within the passage means, to cause the air therewithin to travel therethrough.

7. In a light fixture for an elongated lamp that operates at high temperatures and has a seal at each end thereof, a vertically disposed tubular casing open at end and, a reector having a reiiectorized lower surface mounted in the casing and substantially iilling the vlatter and spaced downwardly from the upper end to form a heating chamber thereabove, a :dichroic filter in and forming part of the reeetor; said lter being adapted to transmit infra-red rays therethrough and to reflect substantially all other rays having a wave length shorter than said infra-red rays to thereby heat the air within the heating chamber, a pair of vertical chimneys connected yto the casing and communicating with the heating chamber at their 4upper ends and each having a portion extending below the reector, said chimneys arranged to permit the passage of air from below the :reflector to the heating chamber, a socket mounted in each chimney below the .reflector to receive an end seal of, and to support, a high temperature lamp below the reflector and the iilter, said sockets being arranged to expose each end seal to the air within the chimney, whereby upon operation of `the lamp, heated air within the chamber will move upwardly, thereby drawing air through the chimney to cool the end seals of the lamp.

8. A light fixture for a lamp as claimed in claim 7 in which the casing extends below the lamp to prevent the passage of air currents -thereover.

9. A light xtnre for a lamp as claimed in claim 7 in which the lamp has an iodine regeneration cycle.

19. In a light fixture for an elongated lamp that operates at high temperatures and has a seal at each end thereof, a vertically tubular casing open at each end, a reector having a reflectorized lower surface mounted in the casing and substantially filling the latter and space-d downwardly from the upper end to form a heating chamber thereabove, a dichroic filter in and forming part of the reflector, said ttilter being adapted to transmit infra-red rays therethrough and to reiiect substantial-ly all other rays having a wave length shorter than said intra-red rays to thereby heat the air within the heating chamber, a pair of vertical chimneys connected to the casing, each havin-g lower portions extending below the reflector and upper portions extending through the heating chamber, said upper portions having a heat transmitting surface to permit the transfer of heat Ifrom the air within the heating chamber to the air within the chimneys to thereby cause circulation of `air therethrough, a socket mounted in each of said .lower portions of each said chimney to receive and end seal of, and :to support, a high temperature lamp below, the reflector and iilter, said sockets being arranged to expose each end seal tothe air within the chimney, whereby upon operation of the lamp heated air within the chimney will move upwardly thereby drawing air therethrough to cool the end sea-ls of the lamp.

11. A light fixture for a lamp Ias claimed in claim 10 in which the casing extends below the lamp to prevent the passage of air currents thereove'r.

12. A light fixture for a lamp as claimed in claim 10 in which the :lamp has an iodine regeneration cycle.

References Cited by the Examiner UNITED STATES PATENTS 2,295,046 9/ 1942 Noel 24o-11.4 2,798,943 7/ 1957 Prideaux 240--47 43,099,403 7/196'3 Strawick 240-47 NORTON ANSH-ER, Primary Examiner. C. R. RHODES, Assistant Examiner. 

1. IN A LIGHT FIXTURE FOR A LAMP THAT OPERATES AT HIGH TEMPERATURE AND HAS AT LEAST ONE SEAL AT AN END THEREOF A REFLECTOR, A FILTER IN THE FORMING PART OF THE REFLECTOR, SAID FILTER BEING ADAPTED TO TRANSMIT INFRA-RED RAYS THERETHROUGH AND TO REFLECT THEREFROM SUBSTANTIALLY ALL OTHER RAYS HAVING A WAVE LENGTH SHORTER THAN SAID INFRA-RED RAYS, HOLDING MEANS FOR SUPPORTING A HIGH TEMPERATURE LAMP IN FRONT OF THE REFLECTOR AND THE FILTER, A HEATING CHAMBER FORMED BEHIND THE REFLECTOR AND INTO WHICH INFRA-RED RAYS ARE DIRECTED BY THE FILTER TO HEAT THE AIR IN SAID CHAMBER, AND PASSAGE MEASN AT SAID HOLDING MEANS AND THROUGH WHICH AIR CAN TRAVEL OVER EACH LAMP SEAL HELD BY SAID HOLDING MERANS, SAID PASAGE MEANS BEING LOCATED RELATIVE TO THE HEATING CHAMBER SO THAT HEAT IN THE LATTER CAUSES AIR TO TRAVEL THROUGH THE PASSAGE MEANS TO COOL EACH LAMP SEAL DURING THE OPERATION OF THE LAMP AND FIXTURE, SAID FILTER COMPRISING A TRANSPARENT CARRIER HAVING A REFLECTIVE FILM COATING ON AT LEAST ONE SURFACE THEREOF. 